Device for harvesting of and tending to shells and for cleaning of an associated shell collector in water

ABSTRACT

A device for example for the harvesting of farmed bivalves ( 6 ) in water ( 4 ), the bivalves ( 6 ) being attached to and growing on a bivalve net ( 10 ) in the water ( 4 ). According to the invention, the device, a bivalve harvester ( 2 ), has a propulsion device arranged thereto, and is formed of a frame with for example at least one rotatable harvesting roller ( 90, 92 ), which is pressed and rotated against the bivalve net ( 10 ) and the bivalves ( 6 ) during the harvesting of the bivalves ( 6 ), so that the bivalves ( 6 ) are thereby scraped or milled loose from the bivalve net ( 10 ), after which the bivalves ( 6 ) are collected and sucked into a catching device enclosing the harvesting roller(s) ( 90, 92 ). The bivalves ( 6 ) and bivalve bunches ( 8 ) are then pumped by means of a pumping device in a downstream direction into a pipe for further transport and collecting onto a vessel or a device placed in the vicinity of the bivalve harvester ( 2 ). Bivalve bunches ( 8 ) may possibly be separated into smaller units in a debunching pipe ( 192 ) placed for example immediately downstream of the catching device.

FIELD OF INVENTION

[0001] This invention relates to a device for use in connection with thefarming of bivalves in farming facilities, wherein the device is usedfor harvesting and tending bivalves, e.g. mussels, in water, thebivalves being lodged on a bivalve collecting device, the device alsobeing applicable for cleaning the bivalve collecting device in water.The farming facilities consist of one or more bivalve collectingdevices, each bivalve collecting device being formed of a seine or a netresembling a fishing net, preferably, but not necessarily, of a coarsemesh. In the position of use, the bivalve collecting device, possiblybivalve collecting devices, in the following referred to as a bivalvenet(s), is/are extended in the surface layer of the water preferably ina vertical, or approximately vertical, direction and preferably to thefull length of the bivalve net, the upper portion, or the headline/support line, of the bivalve net being carried by one or morefloating bodies in the surface, and the bottom portion, or footline/bottom line, being weighted down and tightened by e.g. suitablesinkers or sinking means.

BACKGROUND OF THE INVENTION

[0002] The bivalve net is normally placed in seawater to catch pelagicspat of bivalves which are following the motion of the seawater, andwhich settle on a permanent growing place after some time, the permanentgrowing place consisting, in this case, of bivalve spat catching andfarming facilities formed by one or more bivalve nets. Such bivalvecollecting devices may be used for farming various kinds of bivalves,e.g. mussels.

[0003] In connection with known farming facilities for bivalves, it iscommon opinion and practice that the bivalves should be harvested andtended after their growing place, e.g. a rope or a strip of seine, withthe farmed bivalves attached, has been brought ashore. Such an operationinvolves several drawbacks, many of the drawbacks being avoidable orreducible if harvesting and tending of the farmed bivalves, possiblycleaning of the bivalve collecting device could be carried out in water,and the present invention seeks to solve the technical challengesconnected to harvesting and tending farmed bivalves and cleaning abivalve net in water, preferably in seawater.

[0004] Known Technique

[0005] Devices for harvesting and tending bivalves in water, usuallyseawater, and cleaning associated bivalve net are known to a smalldegree.

[0006] In known forms of farming the bivalves are normally harvested andtended after the growing place with the attached farmed bivalves hasbeen brought ashore.

[0007] Of such forms of farming the farming of bivalves may bementioned, known i.a. from Japan, where for example small scallops areattached equally spaced along a great number of ropes hanging into thesea from floats, and nourish on prey in the form of micro-organisms andother nutrients floating past. The growing place, or the bivalvecollecting device, may also simply consist of one or more ropes, eitherhanging vertically into the sea from above-lying floats, or hanging in acurve between two securing points near the water surface. Instead ofrope(s), the bivalve collecting device may also be formed of one or morestrips of seine (net resembling a fishing net). The attachment andgrowth area on the bivalve collecting device for the pelagic bivalvespat may be increased further through one or more ropes being passedthrough meshes of the net along each strip of seine. The use offine-meshed seine as a bivalve collecting device has also beenattempted.

[0008] Drawbacks of Known Technique

[0009] Harvesting and tending bivalves and cleaning the bivalvecollecting device after they/it have/has been brought ashore is infestedwith a number of drawbacks. In good growing conditions bivalves normallygrow fast and obtain a considerable weight and volume after some time.When the bivalves which are attached to one of more bivalve collectingdevices in farming facilities, are to be lifted out of the water forharvesting or tending, the bivalve collecting device will beconsiderably heavier and more voluminous than when the bi-valvecollecting device was placed in the water. Therefore it may be relevantto dismantle the bivalve collecting device(s) into smaller units whichare easier to handle, but still the work operation of bringing thecomplete bivalve collecting device, or units of it, with the attachedbivalves ashore may require the use of heavy-duty lifting equipment anda relatively large loading area in order for the complete bivalvecollecting device, or units thereof, to be laid down on a suitablevessel or device, e.g. a fish carrier. Besides, all lifting devices andload-carrying components of the bivalve collecting device must be formedand sized to withstand the final weight load applied to the bivalvecollecting device when it is lifted out of the water, and the increasingweight load represented by the growing bivalves during the growingseason in the water. After the bivalve collecting device with theattached bivalves has been brought out of the water, the bivalves areharvested and tended, possibly the bivalve collecting device is cleaned,often by hand, which is time-consuming work as the bivalves have oftengrown into bunches of bivalves, which will then have to be separated,and other organisms, e.g. starfish, and possible unwanted floatingmaterial, e.g. plastic bags and drift wood, must also be removedmanually. Thus, there is a need for making some operations related tothe farming of bivalves more efficient and automated to a greaterextent.

[0010] Due to the small mesh width of the seine, the use of fine-meshedseine may have the effect that the farmed bivalves will grow tighttogether in a short time, so that water rich in oxygen and nutrients isprevented from flowing freely through the bivalve collecting device, andthe farmed bivalves thereby will not have the required growingconditions.

OBJECT OF THE INVENTION

[0011] The device according to the invention should be utilizable forthe harvesting and tending of bivalves and for the cleaning of anassociated bivalve net in connection with bivalve farming, this farmingindustry thus being provided with a way of harvesting and tending thebivalves and cleaning the associated bivalve net in water, preferablyseawater, thereby allowing some opera-ions to be made more efficient andto be automated, so that the above-mentioned drawbacks can be avoided orreduced to a substantial degree.

[0012] Realization of the Object

[0013] The object is realized by the use of a device, in the followingreferred to as a bivalve harvester, in connection with bivalve farming,wherein the bivalve harvester is used for harvesting and tending thebivalves and cleaning the associated bivalve net in water, preferablyseawater. In its position of use the bivalve net is preferably extendedto the total horizontal length of the bivalve net in the surface layerof the water, the head line/carrying line of the bivalve net beingprovided i.a. with one or more floating bodies, preferably in the formof a floating tube/floating hose, floating in or near the surface of thewater. The bivalve net is also extended in a preferably vertical, orapproximately vertical, direction, the foot line/bottom line of thebivalve net being tightened and weighted down by e.g. suitable sinkersor sinking means.

[0014] A suitable vessel or device, e.g. a boat or a raft or raft-likedevice, possibly a land-based device, near the bivalve net/bivalve netsis used in order to place and operate the bivalve harvester in the waterby means of preferably hydraulically activated mechanical devices andpossibly and for example by an electrical manoeuvring and controldevice, the manoeuvring and control preferably being carried out from amobile control panel.

[0015] In order to place the bivalve harvester in the water, the bivalveharvester is lifted from the vessel or the device, possibly from ashore,and placed over the bivalve net and its floating body (bodies), thefloating body/floating bodies preferably being formed of one elongatefloating tube or a floating hose, in the following referred to as afloating tube.

[0016] In principle the bivalve harvester is formed of a frame providedwith at least one harvesting roller-rotatable about its longitudinalaxis, possibly at least one tending or cleaning roller rotatable aboutits longitudinal axis. When the bivalves are being harvested or tended,the bivalve net possibly being cleaned, the relevant roller(s) is (are)placed against the bivalves and/or the bivalve net as the roll(s) is(are) being rotated.

[0017] Such a frame may be formed for example of frame components whichare fixedly connected to each other, the frame being permanentlyarranged to the bivalve net in the water, the frame with the associatedand relevant roller(s) for example being passed over the bivalve net andits floating body (bodies) when being placed in the water. On the otherhand, such a frame solution is impractical and not much flexible, as forexample maintenance of the bivalve harvester and replacing of saidrollers are rendered difficult.

[0018] A more practical and flexible frame solution appears when theframe is formed of two frame parts which are pivotably connected,preferably at their uppermost portion in the position of use, forexample by means of hinges or a hinge device, wherein each hinge orhinge device may be formed of two hinge parts which are interconnectedand are pivotable about a preferably common pivot axle. When two or morehinges are used, the pivot axles of the hinges should have a common axisline. In the water the axis line of the hinges or hinge device runsparallel to, or approximately parallel to, said floating tube.

[0019] The bivalve harvester may be arranged to float in the water bythe floating body (bodies), e.g. the floating tube, of the bivalve net,a floating solution which may be impractical, however, as both thefloating tube and the bivalve net are thereby loaded with the weight ofthe bivalve harvester in water. An alternative to this floating solutionmay be for the bivalve harvester to have a floating device arrangedthereto and surrounding it in the water, for example a raft or raft-likedevice. Another alternative may be that at least one of the frame partsof the bivalve harvester is formed as, or provided with, at least onefloating body, each frame part being provided for example with one ormore floating bodies, e.g. floats, placed at the upper portion of theframe part in use, the floating body or floating bodies providing thebivalve harvester with the necessary buoyancy in water. The floatingbody/floating bodies, possibly the surrounding floating device maymoreover be arranged to be adjustable in the vertical direction andrelative to the bivalve harvester, for example by means of a suitablenumber of spacer elements in the form of ropes, chains, flat irons,plates or similar, and so that the bivalve harvester can be placedaround the bivalve net at the relevant depth in the water. When thebivalve harvester is placed in an open position in the water, preferablythe lower portions of the frame parts are arranged to be pushed apart,for example by means of at least one hydraulically operated cylinderpositioned between the frame parts. In its open position the bivalveharvester is placed around and preferably over the bivalve net, oneframe part on either side of the bivalve net. Then preferably the lowerportions of the two frame parts are pulled together into a lockedposition, for example by means of said hydraulically operated cylinder,and preferably so that they can be locked together by means of at leastone releasable locking device. In their closed and locked position ofuse, the frame parts of the bivalve harvester are arranged to encompassthe bivalve net in the full vertical, or approximately vertical, lengthof the bivalve net, including the head line and the foot line, and overa certain horizontal length of the bivalve net. Thereby a region or areaof the bivalve net is completely enclosed by the frame parts of thebivalve harvester, and the harvesting or tending of the farmed bivalves,possibly cleaning of the bivalve net, may then be commenced, preferablyfrom one of the ends of the bivalve net. The bivalve harvester thenmoves by means of a propulsion device, and at a suitable speed along thebivalve net in the water, harvesting or tending the bivalves that havelodged on the bivalve net, or possibly cleaning the bivalve net.Harvested bivalves, possibly collected waste organisms/waste, are thenpreferably pumped up and collected on the vessel, device or, morerarely, on shore. Collected waste organisms/waste may possibly, whenconditions allow it, be pumped out directly and deposited directly inthe water.

[0020] The two frame parts of the bivalve harvester, which arepreferably of a square or rectangular shape, are cooperatingly andpivotably connected, each frame part being provided with a respectivejoining side, possibly joining portion, forming the upper portion of theframe part in the position of use, and an opposite side, possibly anopposite portion, preferably forming the lower potion of the frame partin the position of use, which sides or portions are spaced apart andconnected by means of connecting sides, possibly connecting portions,the frame parts being pivotably connected along their joining sides orjoining portions. As mentioned, the joining sides or joining portions ofthe frame parts, may be hinged together in the position of use, so thatthey can be pivoted relative to one another about a common horizontal,or approximately horizontal, axis line, so that the other sides orportions of the frame parts may thereby be opened and closed, forexample by means of said hydraulic cylinder.

[0021] At least one of the frame parts is provided with at least oneharvesting roller or tending roller, possibly at least one cleaningroller, which is rotatable about its longitudinal axis, the longitudinalaxis extending vertically, or approximately vertically, between thejoining side or the joining portion and the opposite side or portion inthe position of use. Alternatively, at least one cooperating pair ofrollers may be used, wherein the pair of rollers is placed, in theposition of use, with one roller on either side of the bivalve net, andwherein, especially in the harvesting of bivalves, it will be ofadvantage to use two cooperating harvesting rollers, or a pair ofharvesting rollers. In the tending of bivalves, for example whenthinning the stock of bivalves, it may be relevant to use only onetending roller on one of the sides of the bivalve net.

[0022] As mentioned, such rollers are rotatable about their longitudinalaxes and may be rotated by a motor, and possibly at least one roller ofa pair of cooperating rollers is rotated by a motor, possibly bothrollers of each pair of cooperating rollers are rotated by a motor each,such a motor preferably being of the infinitely variable and reversiblekind. In its position of use the motor is arranged to the roller andpreferably positioned immediately underneath it, the motor being poweredfor example electrically or hydraulically. In addition each roller isattached to its frame part preferably by means of a releasable supportdevice, so that one type of roller can easily be replaced by anothertype of roller, for example a harvesting roller may be replaced by atending roller or a cleaning roller.

[0023] The external shape of a roller depends on the task the roller isto perform in the harvesting and tending of the farmed bivalves.Therefore, a harvesting roller may-be formed or provided, for example,with profiled ribs, teeth, strings, threads or brushes. A tending rolleror a cleaning roller, on the other hand, is preferably provided withthreads, strings or brushes, and a tending roller is formed, forexample, with wires, whereas a cleaning roller is formed with anotherand softer type of thread, the tending or cleaning roller possiblycooperating with a separate, but complementary, tending or cleaningbrush positioned stationary to the frame part, this brush being formedfor example with a type of thread corresponding to that of thecomplementary roller, so that unwanted organisms, e.g. starfish, andother waste may thereby be removed from the bivalve net.

[0024] When the bivalve harvester is closed and locked in its positionof use, the bivalve harvester is moved in the direction of propulsion bya suitable propulsion device. Such a propulsion device may be arrangeddirectly or indirectly to the bivalve harvester. A propulsion devicearranged directly to the bivalve harvester may for example be formed byat least one propulsion roller, rotatable about its longitudinal axis,the longitudinal axis running vertically, or approximately vertically,between the joining side or the joining portion and the opposite side orportion of at least one frame part, in the position of use. Thepropulsion roller(s) is (are) pressed against the bivalve net, while, atthe same time, the propulsion roller(s) is (are) being rotated, so thatthe bivalve harvester is thereby moved in the direction of propulsionalong the bivalve net. A propulsion device indirectly arranged to thebivalve harvester may for example be formed by an arrangement of cables,wires or ropes and tackles, the cables, wires or ropes being arranged atone end to the bivalve harvester and being arranged at the other-end toe.g. a winch located for example on shore, the winch pulling the bivalveharvester in the desired direction along the bivalve net. The bivalveharvester may alternatively and for example have a surrounding floatingdevice arranged thereto, e.g. a raft or raft-like device, this deviceotherwise being arranged with a propulsion device which is arranged tothe floating tube of the bivalve net, for example by means of one ormore suitable wheels or rollers, so that the device, and thereby thebivalve harvester, is moved in a desired direction of propulsion alongthe bivalve net.

[0025] When one or more propulsion rollers arranged to the bivalveharvester itself, are used, it will be of advantage to use at least twocooperating propulsion rollers, or a pair of propulsion rollers, saidpair of rollers being positioned, in its position of use, with oneroller on each side of the bivalve net, the rollers being pressedsufficiently hard against one another and against the intermediatebivalve net, while, at the same time, the rollers are being rotated, sothat the bivalve harvester is moved in the desired direction of motionalong the bivalve net. Like the harvesting, tending or cleaning rollers,the propulsion rollers may be rotated by a-corresponding motor, at leastone roller of a pair of cooperating rollers being rotated by a motor,possibly both rollers of each pair of cooperating rollers being rotatedby a motor each. Correspondingly, in its position of use, the motor maybe arranged to the roller immediately below it, the roller preferablybeing releasably supported in the associated frame part and therebybeing exchangeable or replaceable. A propulsion roller may be providedwith for example a cylindrical and evenly formed rubber membrane at itsouter surface, or this surface may be provided with rubber knobs orpossibly projecting teeth.

[0026] When one or more pairs of propulsion rollers is (are) used forthe propulsion of the bivalve harvester, the propulsion rollers shouldbe placed, seen relative to the moving direction, to the rear of theharvesting, tending or cleaning roller(s), the propulsion rollersthereby being pressed against the bivalve net and not against theattached bivalves. Propulsion of the bivalve harvester is provided inthat the propulsion roller(s) on the right-hand side of the bivalve net,as seen from above and in the direction of motion, is (are) rotatedanti-clockwise, whereas the propulsion roller(s) on the left-hand sideof the bivalve net will have to be rotated clockwise. At the same timethe harvesting, tending or cleaning roller(s) on the right-hand side ofthe bivalve net are rotated clockwise, whereas the harvesting, tendingor cleaning roller(s) on the left-hand side of the bivalve net is (are)rotated anti-clockwise, the rollers on both sides of the bivalve netpreferably being rotated at the same peripheral speed. Thereby thebivalve net between the propulsion rollers and harvesting, tending orcleaning roller(s) is held stretched, so that harvesting or tending ofthe bivalves, possibly cleaning of the bivalve net, proceeds more easilythan if the bivalve net was not subjected to such stretching. Asmentioned, both propulsion rollers of a pair of propulsion rollers maybe rotated by a motor each, but each propulsion roller should be rotatedat preferably equal peripheral speed. Alternatively and preferably onlyone of the propulsion rollers of the pair of rollers should be rotatedby a motor, so that this propulsion roller is the moving propulsionroller, whereas, as a consequence of the pressing together of the twopropulsion rollers, the other propulsion roller will follow passively inthe rotational motion.

[0027] The clamping force of the rollers of a pair of rollers, andthereby the clamping force between each roller and the bivalve net, maypossible be adjusted to the desired clamping force, for example byadjustment of the distance between the roller and the associated framepart, each roller preferably being positioned closer to the bivalve netthan the respective frame part of each roller. This may be achieved, forexample by positioning a hydraulic cylinder, or other spring device, orone or more mechanical spacer elements, possibly a similar device(devices), between the frame part and the points of support of theassociated roller. Thereby the clamping force of the rollers of a pairof rollers, and thereby the clamping force between each roller and thebivalve net, may be adjusted as required, for example so that thebivalves are not crushed, and/or to achieve the desired frictional forcebetween the bivalve net and the rollers, and preferably when the bivalveharvester is used in water. By the use of a hydraulic cylinder for thispurpose, the clamping force of the cylinder may possibly be adjusted bymeans of known control technique, for example by means of at least onepressure sensor with other and necessary control arrangements/devicesfor such control-technical use arranged thereto.

[0028] Preferably, when pairs of harvesting, tending or cleaning rollersare used, the rollers of a pair of rollers should be somewhat staggeredrelative and parallel to one another and longitudinally of the bivalvenet. When the bivalve harvester is closed and locked in its position ofuse, the harvesting and tending rollers are, in principle, pressedsufficiently hard and perpendicularly against the bivalves on thebivalve net, possibly the cleaning rollers against the bivalve net, therollers of a pair of rollers being positioned on one side each of thebivalve net. Thereby the rollers do not exert a direct clamping forceagainst each other, which spares the bivalves from being crushed duringharvesting or tending, or which spares the bivalve net unnecessary wearwhen being cleaned.

[0029] The bivalves separated from the bivalve net are then caught in acatching device, e.g. a net, a sleeve or interconnected plates,completely or partially surrounding the harvesting roller(s) along theentire length(s) of the roller(s), or along parts thereof. The catchingdevice may for example be divided into two equal, or approximatelyequal, catching sections which cooperate with and run parallel to theroller(s) in the position of use, the catching sections being arrangedto a frame part each, so that the two sections are separated from eachother when the bivalve harvester appears in its open position. As thebivalves are being-tended, possibly the bivalve net being cleaned, thewaste organisms and/or the waste may be caught, in a manner similar tothat of the harvesting of bivalves, in the catching device along theentire length(s) of the tending or cleaning roller(s), or along partsthereof. Alternatively the catching device may possibly be temporarilyremoved from the bivalve harvester, so that, when advisable, the wasteorganisms and/or the waste may be directed directly into the surroundingwater.

[0030] In its position of use the catching device is preferably openthrough at least two ends or portions, one of these ends or portions,preferably located at the lower portion of the bivalve harvester, havingan opening of a pipe arranged thereto through a transition device, e.g.a funnel. By means of a pumping device arranged directly or indirectlyto this pipe, water containing the bivalves and the bunches of bivalves,possibly the waste organisms/waste, is pumped through the catchingdevice and further downstream through the pipe. The pipe, e.g. aconveyor pipe, carries the flow of water containing the bivalves and thebunches of bivalves, possibly also waste organisms and other waste,further up to the vessel or device, possibly onto the shore. Asmentioned, when bivalves are being tended, possibly the bivalve netbeing cleaned waste organisms and other waste may, when advisable,possibly be directed directly into the water, for example into theseawater.

[0031] The above-mentioned pipe may for example have a so-calleddebunching pipe arranged thereto. This debunching pipe may be placed forexample in the immediate vicinity and downstream of the catching device.Alternatively the debunching pipe may be located for example on thevessel or a suitable device, possibly on shore. As the name suggests,the debunching pipe is used in order to break apart, or debunch, bunchesof bivalves, bivalves often growing together into bunches on the bivalvenet. Such bunches of farmed bivalves must normally be broken apart forthe purpose of facilitating the subsequent packing, transport and salesof the bivalves.

[0032] A debunching pipe is preferably of a straight and elongateconfiguration, and in its position of use, it is placed and securedunderneath one of the two frame parts of the bivalve harvester forexample, so that on propulsion of the bivalve harvester in the water,the debunching pipe runs unobstructed underneath the foot line of thebivalve net. The debunching pipe is arranged internally with adebunching device, which may be formed for example of a stator part,which cooperates with a preferably adjacent rotor part in order to breakup the bunches of bivalves, the two cooperating parts being referred toin the following as a debunching unit, and longitudinally, thedebunching pipe may possibly be provided with one or more suchdebunching units.

[0033] When one or more such debunching units are used, the stator androtor parts are each provided with, for example, vanes, blades, stringsor threads of a suitable configuration, size and of a suitable material,and are present in an adequate number. The stator part is formed of suchvanes, blades, strings or threads which are anchored, and preferablyreleasably anchored, to the internal surface of the debunching pipe,whereas the rotor part is formed of such vanes, blades, etc., anchored,and preferably releasably anchored, to a rotary axle positioned alongthe centre line of the debunching pipe. For the rest, the debunchingpipe may be formed of two preferably similar and releasable halves, sothat these may easily be separated for the purpose of replacing,possibly repairing, the rotary axle and/or one or more debunching units,possibly individual vanes, blades, strings or threads.

[0034] The vanes, blades, strings and/or threads of the stator and rotorparts are preferably positioned radially about the centre line of thedebunching pipe, and preferably so that the vanes, blades etc. aredistributed by an identical angle distance along a common imaginarycircumferential line. On the side opposite their anchoring points, thevanes, blades etc. may possibly be secured equidistantly along acircular ring, so that the free ends of the vanes, blades, strings orthreads along this ring are connected to each other, such a connectionbeing more rigid and stronger than if the individual vanes, blades, etc.were only anchored on one side.

[0035] As mentioned, in its position of use the stator part of thedebunching unit cooperates with a rotor part, the rotor part beingarranged sufficiently close to, preferably in the immediate vicinity of,the stator part, as the rotary axle with the rotor part mounted thereonis rotated. When a bunch of bivalves is carried by the water flow intothe gaps between the vanes, blades, strings or threads of the rotor partand the stator part, the bivalve bunch may, as a consequence of therelative movement of the rotor part and the stator part, be broken intosmaller bivalve bunches and individual bivalves. To prevent the bivalvesfrom being crushed or damaged in the debunching process, all or some ofthe vanes, blades, strings or threads may possibly be provided with, orbe formed entirely or partially from relatively soft materials, e.g. asuitable rubber material. Additionally, depending on for example thebivalve type and/or bivalve size, different types, possibly differentconfigurations and/or combinations, of vanes, blades, strings or threadsmay be used in the rotor part and/or the cooperating stator part.

[0036] Several such debunching units may be used, wherein the debunchingunits are spaced apart, and the distance between each successivedebunching unit, or each debunching step, may be the same or preferablydecreasing, seen in the downstream direction of the water flowingthrough the debunching pipe. In principle the bivalve bunches shouldhave been separated completely, or approximately completely, intoindividual bivalves when the bivalves leave the debunching pipe. The useof several such debunching units may therefore be required in order toseparate the bunches of bivalves sufficiently well in two or moredebunching steps, so that finally, and to the greatest degree possible,the bivalves will appear as individual bivalves. To accomplish this,different types, possibly different configurations and/or combinations,of vanes, blades, strings and/or threads may be used in each, possiblysome, of the successive debunching steps and possibly within eachindividual debunching unit. In the tending of the bivalves, or in thecleaning of the bivalve net, possibly and for example the rotary axleand all, possibly some, of the vanes, blades, strings and/or threads maybe removed or replaced by other suitable types of vanes, blades, stringsand/or threads, which are possibly better suited for the tending andcleaning purposes. Alternatively the rotary axle may simply be leftunactivated.

[0037] The rotary axle with the rotor part(s) attached thereto can bemoved and rotated by a preferably hydraulically or electrically drivenmotor, for example of an infinitely variable and reversible kind, whichis possibly controlled from a mobile control panel on the vessel ordevice, possibly from ashore. This motor is preferably arranged to therotary axle and preferably at the downstream end thereof.

[0038] Separated bivalves and/or bivalve bunches, possibly collectedwaste organisms/waste, are transported further in the flow of water bymeans of a pumping device, and in a downstream direction by a conveyorof a suitable type and size, which extends up to the vessel or thedevice, or, more rarely, onto the shore.

[0039] The pumping device pumping the water containing the bivalvesand/or the bivalve bunches, possibly waste organisms/waste, must bearranged to the pipe located downstream of the catching device. Such apumping device may, in principle, be placed anywhere along or inconnection with this pipe, for example immediately downstream of thedebunching pipe, or on the vessel or device, or more rarely on shore.The pumping device is formed by for example a pump and an associateddriving motor, e.g. a remote-controlled and infinitely variablehydraulically or electrically driven motor. Non-limiting examples ofsuch pumping devices are injector pumps, vacuum pumps, airlift pumps andcentrifugal pumps.

[0040] On the vessel or device the bivalves may then be collected insuitable containers, e.g. cases, storage tanks or wells, e.g. on a fishcarrier or in a collecting enclosure, after which possible furtherprocessing and/or further transport is carried out before the bivalvesare distributed and possibly consumed. Unwanted organisms, e.g.starfish, and any other waste may correspondingly be collected insuitable storage containers or, when advisable, be deposited in thewater/sea, as mentioned.

[0041] Advantages Achieved Through the Invention

[0042] The most obvious advantage of the invention is that farmedbivalves attached to a bivalve collecting device in the form of abivalve net may be harvested and tended in their natural growing placein water, preferably in seawater, and the possibility of cleaning thebivalve net in water. Thereby, having to dismantle and remount thewhole, or units of, the bivalve collecting device before it/they is/arelifted ashore or aboard a suitable vessel or device for the harvestingand tending of the bivalves, possibly cleaning of the bivalve net, isavoided, such harvesting and tending, possibly such cleaning, normallybeing time-consuming and often being carried out manually. Possiblyhaving to use heavy-duty lifting equipment for heavy lifts of the wholeor parts of the bivalve collecting device and the farmed fish attachedthereto, is thereby avoided, which heavy lifts could also cause damageto the bivalve net and the bivalves. By the very fact that harvestingand tending, possibly cleaning, are carried out in water, all liftingdevices and load-carrying components of the bivalve collecting devicemay be formed and sized to resist a smaller weight load than when thebivalve collecting device and the attached bivalves have to be liftedout of the water. The use of the bivalve harvester also results in lesstime-consuming, more efficient and, to a greater degree automatedharvesting and tending of the-bivalves, possibly cleaning of the bivalvenet. This makes it possible, for example, for the bivalves to bedelivered from the vessel, device, fish carrier or collecting enclosuresin a fully, or approximately fully, prepared state for furtherprocessing, transport and sale, or for possible waste or waste organismsto be delivered from the vessel or device in a totally collected state,possibly for such waste to be deposited in the water, when advisable.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS

[0043] In the following part of the description, and referring to theFIGS. 1-9, there will be shown one non-limiting exemplary embodiment ofthe bivalve harvester, as it is being used, and exemplary embodiments ofrollers included in the bivalve harvester, one particular referencenumeral referring to the same detail in all drawings, in which thisdetail is identified, wherein

[0044]FIG. 1 shows a view of the bivalve harvester seen along thevertical line of section IV-IV, cf. FIGS. 2 and 3, the bivalve harvesterbeing shown in an open position, while hanging on a wire and being aboutto be placed about the bivalve net in the water;

[0045]FIG. 2 shows a view and vertical partial section II-II, Cf. FIG.3, FIG. 4 and FIG. 5, of a bivalve harvester according to the invention,the bivalve harvester being placed in its position of use over acoarse-meshed bivalve net in the water, wherein farmed bivalves attachedto the bivalve net are harvested by means of the bivalve harvester whichis moving horizontally in the water and along the bivalve net. Thedrawing also indicates a horizontal line of section III-III and verticallines of section IV-IV and V-V;

[0046]FIG. 3 shows a horizontal section III-III, cf. FIG. 2, FIG. 4 andFIG. 5, of the bivalve harvester during harvesting of farmed bivalves inthe water, wherein the bivalve harvester is moved forward along thebivalve net by means of a pair of propulsion rollers positioned aroundthe bivalve net at the rear portion (relative to the direction ofpropulsion) of the bivalve harvester, and wherein the harvesting of thebivalves is carried out by a pair of harvesting rollers placed aroundthe bivalve net at the front portion of the bivalve harvester. Thedrawing also indicates vertical lines of section II-II, IV-IV and V-V;

[0047]FIG. 4 shows, like FIG. 1, a view of the bivalve harvester seenalong the vertical line of section IV-IV, cf. FIG. 2 and FIG. 3, but thebivalve harvester is shown in a closed position round the bivalve net,one propulsion roller bearing on either side of the bivalve net andpressing against it, the pair of propulsion rollers moving the bivalveharvester in the direction of propulsion. The drawing also indicates thehorizontal line of section III-III and vertical line of section II-II;

[0048]FIG. 5 shows a view of the bivalve harvester seen along thevertical line of section V-V, cf. FIG. 2 and FIG. 3, the bivalveharvester being shown in a closed position around the bivalve net, oneharvesting roller bearing on each side of the bivalve net, the bivalvesbeing harvested by means of the pair of harvesting rollers. The drawingalso indicates the horizontal line of section III-III and vertical lineof section II-II;

[0049]FIG. 6 shows one example of a propulsion roller, formed with arubber membrane at its outer surface;

[0050]FIG. 7 shows one example of a propulsion roller, provided withrubber knobs at its outer surface;

[0051]FIG. 8 shows one example of a harvesting roller, which hasprofiled strips attached to its outer surface; and

[0052]FIG. 9 shows one example of a tending or cleaning roller withouter threads attached thereto, the tending or cleaning roller bearingin a cooperating manner on a tending or cleaning brush, also withthreads attached thereto, wherein unwanted organisms and possibly otherunwanted material attached to the tending or cleaning roller may beremoved by rotation of the tending or cleaning roller, and by thethreads attached to the roller thereby being scraped or rubbed againstthe non-rotating threads of the tending or cleaning brush.

[0053] It should be noted that all drawings are distorted as regardssizes and distances.

DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

[0054] Equipment and/or arrangements which do not concern the inventionitself, but otherwise are or may be necessary conditions for practicingthe invention, will not be specified further or more thoroughlydescribed in the following exemplary embodiment. Such equipment and/orarrangement comprises a vessel or device, e.g. a boat or a raft orraft-like device, not shown in the drawn figures, from/td which abivalve harvester 2 is lifted from and into the water 4, preferablyseawater, and from which it is operated, and from/to which harvestedbivalves 6 or bivalve bunches 8, possibly waste, e.g. starfish, plasticbags or drift wood, are conveyed. The vessel or device is also providedwith other necessary devices, e.g. a hoisting device, hydraulic and/orelectric auxiliary and controlling systems and equipment, and possiblyother equipment necessary for carrying out harvesting and tending of thefarmed bivalves 6, in the following referred to as the bivalves 6, on abivalve net 10, and possibly for cleaning the bivalve net 10. Thepresence of a bivalve net 10, in this case a coarse-meshed bivalve net10, in the water 4 is also an absolute condition for the practicing ofthe invention, the bivalve net 10 being extended to its full length inthe water 4 and hanging vertically, or approximately vertically, intothe water 4, and the bivalve net 10 being provided, at its upperportion, with a headline 12 (a support line) connected to a continuousfloating tube 14 extending in the full length of the bivalve net 10 andproviding the bivalve net 10 with the necessary buoyancy. A lowerportion, or foot line 15 (a bottom line) of the bivalve net 10 isweighted down and stretched by suitable sinkers 16.

[0055] The bivalve harvester 2 is formed by two hingedly connected andcooperating frame parts 18 and 20, the frame parts 18 and 20 being of asquare or rectangular configuration, and each frame part 18 or 20 beingformed by one top side 22 or 24 and one opposite bottom side 26 or 28,which are horizontal, or approximately horizontal, in the position ofuse, and each frame part 18 or 20 additionally being formed by twovertical, or approximately vertical, connecting sides 30 and 30′,respectively 32 and 32′, arranged in pairs and spaced apart. Theconnecting sides 30 and 30′ of the frame part 18 are shorter than theconnecting sides 32 and 32′ of the frame part 20. Moreover, the framepart 18 has a debunching pipe 192, which will be described later,arranged thereto by two angular stays 33 and 33′, the angular stays 33and 33′ being positioned underneath the frame part 18 in the position ofuse and arranged thereto by means of a releasable locking device each,which will be described later.

[0056] Along their top sides 22 and 24, the frame parts 18 and 20 eachhave two connecting stays 34 and 35, 34′ and 35′, respectively, arrangedthereto and spaced apart, the connecting stays 34 and 35 and theconnecting stays 34′ and 35′ projecting for example horizontally and atright angles from their top sides 22 and 24. The connecting stays 34 and34′ and the connecting stays 35 and 35′, in pairs, have a respectivehinge 36 and 37 arranged thereto, the hinges 36 and 37 being spacedapart. The hinges 36 and 37 are each formed of two hinge parts 38 and38′, 40 and 40′, respectively, connected in pairs. The hinge parts 38and 38 each have a connecting stay 34 and 34′ arranged thereto, whereasthe hinge parts 40 and 40′ each have a connecting stay 35 and 35′arranged thereto. The hinge parts 38 and 38′ are pivoted relative to oneanother about a common pivot axle 42 positioned in the hinge 36, whereasthe hinge parts 40 and 40′ are pivoted relative to one another about acommon pivot axle 44 positioned in the hinge 37. The pivot axles 42 and44 have a common axis line, extending, in the position of use, parallelto, or approximately parallel to, said floating tube 14 in the water 4.Thereby the frame parts 18 and 20 are pivotable relative to one another,so that the bivalve harvester 2 can be opened and closed around thebivalve net 10.

[0057] Each hinge part 38, 38′, 40 and 40′ is formed as one half of acylinder, of a semicircular cross-section. Hinged together twocooperating hinge parts 38 and 38′ and 40 and 40′ may therefore beclosed around the floating tube 14 of the bivalve net 10, so that intheir closed position they adopt a cylindrical shape. On their internalsurfaces and longitudinally to the floating tube 14, the hinge parts 38and 38′ of the hinge 36 are provided with four longitudinal glidingstrips 46, 48, 50 and 52. Correspondingly, on its internal surfaces andlongitudinally to the floating tube 14, the hinge 37 is provided withfour longitudinal gliding strips 46′, 48′, 50′ and 52′. At their endportions the gliding strips 46, 48, 50 and 52, and the gliding strips46′, 48′, 50′ and 52′ take a wedged shape, whereby their end portionsavoid getting stuck in the bivalve net 10 as the bivalve harvester 2 isdriven forward. Alternatively said gliding strips 46, 48, 50 and 52, andthe gliding strips 46′, 48′, 50′ and 52 may be replaced for example by asuitable number of rollers, not shown, suitably positioned on theinternal surfaces of the hinge parts 38, 38′, 40 and 40′.

[0058] Opening and closing of the frame parts 18 and 20 may beeffected-by two for example remote-controlled and double-actinghydraulic cylinders 54 and 56 connected to a hinge 36 and 37 each. Inthis exemplary embodiment the cylinders 54 and 56 are each placedbetween two stays 58 and 58′ and 60 and 60′, which extend upwards in theposition of use, each end portion of the cylinder 54 and the cylinder56, respectively, being rotatably connected to the upper end of arespective stay 58 and 58′, or a respective stay 60 and 60′. Each stay58 and 58′, or each stay 60 and 60′, are fixedly arranged to arespective hinge part 38 and 38′ of the hinge 36, and a respective hingepart 40 and 40′ of the hinge 37. In their contracted position thehydraulic cylinders 54 and 56 will thus cause the frame parts 18 and 20to open relative to one another, cf. FIG. 1, whereas in their extendedposition the hydraulic cylinders 54 and 56 cause the frame parts 18 and20 to close relative to one another, cf. FIG. 4 and FIG. 5.

[0059] By means of the above-mentioned devices the bivalve harvester 2is then placed in an open position over the bivalve net 10 in the water4 while the bivalve harvester 2 is hanging on a wire 62. Referring toFIG. 1, the wire 62 is attached at one end to a lifting lug 64 on thebivalve harvester 2, whereas at its opposite end the wire 62 isconnected to a hoisting device on the adjacent vessel or device, notshown. The bivalve harvester 2 is then lowered sufficiently far into thewater 4 for the frame parts 18 and 20 of the bivalve harvester 2 toclose completely around the bivalve net 10, its headline 12 and footline 15, and its sinkers 16 and floating tube 14.

[0060] The frame parts 18 and 20 are then locked together in the closedposition by means of two identical and releasable locking devices, onelocking device being located between the angular stay 33 and the bottomside 26 of the frame part 18, the other locking device being locatedbetween the angular stay 33′ and the bottom side 26 of the frame part18. The locking devices are each formed of a pivotable locking hook 66or 67, each having a for example remotely controlled and double-actinghydraulic cylinder 68 or 69 arranged thereto. The hydraulic cylinders 68and 69 are rotatably arranged to the frame part 18 by means of arespective mounting plate 70 and 72, and the locking hooks 66 and 67 arepivotably arranged to the frame part 18 by means of a respectivemounting plate 70′ and 72′. The frame parts 18 and 20 of the bivalveharvester 2 are locked together in their closed position by thehydraulic cylinder 68 and 69 pushing, and thereby pivoting, the lockinghooks 66 and 67 into engagement in a respective complementarily formedhook retainer 74 and 75, the hook retainer 74 being attached to theangular stay 33, and the hook retainer 75 being attached to the angularstay 33′, cf. FIGS. 4 and 5. The hook retainers 74 and 75 are formed atthe same time with a plate 76 and 77 each, which are vertical in theposition of use, extending upwards within the angular stays 33 and 33′,the plates 76 and 77 serving as abutment surfaces, against which theframe part 18 abuts, when the frame part 18 is to be closed togetherwith the frame part 20. Otherwise the locking hook 66 is shown in itsopen and detached position in FIG. 1.

[0061] Placed over the bivalve net 10, the bivalve harvester 2 is keptfloating in the water 4 by-means of two floats 78 and 80 arranged at theupper portion of each frame part 18 and 20, each of the floats 78 and 80being secured to the frame parts 18 and 20 by means of a mounting plate81 or 84 each, and straps, fastening bands or similar fasteners, notshown in the drawings. If the bivalve net 10 is kept floating at acertain depth below the water surface, the straps, fastening bands orsimilar fasteners may possibly be adjusted in the vertical longitudinaldirection, so that the bivalve harvester 2 is floating at a desireddepth relative to the bivalve net 10. Otherwise the adjusting device isnot shown in the drawings. Additionally, the floats 78 and 80 maypossibly be ballasted.

[0062] In its closed and locked position the bivalve harvester 2 movesat a suitable speed in the direction of motion and along the bivalve net10, preferably from one of the ends of the bivalve net 10, harvesting ortending, e.g. thinning, the bivalves 6 on the bivalve net 10, orpossibly cleaning the bivalve net 10.

[0063] Seen relative to the moving direction of the bivalve harvester 2,propulsion of the bivalve harvester 2 and harvesting, possibly tending,of the bivalves 6, possible cleaning of the bivalve net 10, are effectedby means of one front pair and one rear pair of rollers, each pair ofrollers appearing in its position of use with one roller on each side ofthe bivalve net 10, the rollers of each pair, and the pairs betweenthemselves, cooperating as the rollers are positioned parallel to eachother. The front and rear pairs of rollers are placed at equal height(or depth) about the bivalve net 10. Propulsion of the bivalve harvester2 is effected by the rear pair of rollers, formed by two cooperatingpropulsion rollers 86 and 88, whereas harvesting of the bivalves 6,possibly tending of the bivalves 6 or cleaning of the bivalve net 10, iseffected by the front pair of rollers, which is formed by twocooperating harvesting rollers 90 and 92, possibly two tending orcleaning rollers 94 and 96. It is pointed out that tending, e.g.thinning, of the bivalves 6, possibly cleaning of the bivalve net 10,may be carried out by just one tending or cleaning roller 94 or 96,wherein only one side of the bivalve net (10) is thereby being tended,possibly cleaned.

[0064] Propulsion of the bivalve harvester 2 is provided by twocooperated propulsion rollers 86 and 88 attached to a respective framepart 18 and 20. Each propulsion roller 86 and 88 is elongate androtatable about its longitudinal axis, the propulsion rollers 86 and 88running vertically, or approximately vertically, from their top sides 22and 24 to their opposite bottom sides 26 and 28 of the frame parts 18and 20, in their position of use. When the bivalve harvester 2 is closedand locked in its position of use, the propulsion rollers 86 and 88 arepressed sufficiently hard and, relative to the intermediate bivalve net10, at right angles against one another. At its outer surface each ofthe propulsion rollers 86 and 88 in the exemplary embodiment is formedwith a cylindrical and evenly formed rubber membrane 98 and 98′, cf.FIG. 6. Alternatively each propulsion roller 86 and 88 may be providedwith for example rubber knobs 100 on its outer surface, cf. FIG. 7, orfor example projecting teeth. As the two propulsion rollers 86 and 88are forced against each other and against the bivalve net 10 whilerotating, sufficient friction is created between them for the bivalveharvester 2 to be moved in the desired direction along the bivalve net10. Seen from above and in the moving direction, the propulsion roller88 on the right-hand side of the bivalve net 100 must therefore berotated anti-clockwise, whereas the propulsion roller 86 on theleft-hand side of the bivalve net 10 must be rotated clockwise.Longitudinally, each propulsion roller 86 and 88 is provided with arespective rotatable through centre axle 102 and 104, each of the centreaxles 102 and 104 being attached at their end portions to a respectivepropulsion roller 86 or 88 by means of two circular mounting plates 106and 108, each provided with a centred hole 110 and 112, through whichthe centre axle 102 or 104 is passed, cf. FIGS. 6 and 7. To provide therequired rotary motion, each centre axle 102 and 104 has, at its lowerend portion in the position of use, a respective hydraulic motor 114 and116 arranged thereto, which is for example, remotely controlled,infinitely variable and reversible. In an alternative not shown, onlyone of the propulsion rollers 86 and 88 is driven by a hydraulic motor114 or 116. In use each propulsion roller 86 and 88 is driven atpreferably equal peripheral speed. The motors 114 and 116 are eachattached to a respective spacer element 118 and 120, each arranged to arespective mounting plate 122 and 124, each mounting plate 122 and 124being arranged to a respective frame part 18 and 20. In addition eachpropulsion roller 86 and 88 is releasably supported at its upper endportion on a respective bearing pedestal 126 and 128, which is securedto a respective spacer element 130 and 132, the spacer elements 130 and132 being arranged to a respective frame part 18 and 21 by means of amounting plate 134 and 136 each. The propulsion rollers 86 and 88 mayfor example be releasably supported on the frame parts 18 and 20 bymeans of a lockable hinge-lid, not shown, arranged to each of thebearing pedestals 126 and 128. Thereby one or both of the propulsionrollers 86 and 88 and/or one or both of the harvesting rollers 90 and92, possibly one or both of the tending or cleaning rollers 94 and 96,may be exchanged or replaced when necessary. The compressive forcebetween the propulsion rollers 86 and 88 may possibly be adjusted byadjusting the distance between the relevant propulsion roller 86 or 88and the associated frame part 18 or 20, which can be achieved throughadjustment of the spacer elements 118 and 120 and the spacer elements130 132. This may be achieved, for example, by placing a hydrauliccylinder not shown, or a spring device not shown, or one or moremechanical spacer elements not shown, or a similar device/devices notshown, between the support points of the frame part 18 and thepropulsion roller 86 and the frame part 20 and the propulsion roller 88,possibly between those of the frame part 18 and the harvesting roller 90and the frame part 20 and the harvesting roller 92, possibly betweenthose of the frame part 18 and the tending or cleaning roller 94 and theframe part 20 and the tending or cleaning roller 96, moreover not shownin the drawings. Thereby, as required, for example the clamping forcebetween the propulsion rollers 86 and 88, and thereby the frictionalforce between the bivalve net 10 and the propulsion rollers 86 and 88,may be adjusted, or the clamping force between the bivalves 6 on thebivalve net 10 and a harvesting roller 90 and/or 92 may possibly beadjusted, or for example the clamping force between the bivalve net 10and a tending or cleaning roller 94 and/or 96 may be adjusted.

[0065] Harvesting and tending of the bivalves 6, possibly cleaning ofthe bivalve net 10, is effected by means of the front pair of rollers,the front pair of rollers being formed by two cooperating harvestingrollers 90 and 92, possibly by two cooperating tending or cleaningrollers 94 and 96. In the following description the assembly andfunction of a pair of harvesting rollers will be explained, the assemblyand function of a pair of tending or cleaning rollers beingapproximately identical to the assembly and function of a pair ofharvesting rollers.

[0066] When the bivalve harvester 2 is closed and locked in its positionof use, the harvesting rollers 90 and 92 are forced adequately hardagainst the bivalves 6 on the bivalve net 10 not to break them. Unlikethe positioning of the propulsion rollers 86 and 88 in the bivalveharvester 2, the harvesting rollers 90 and 92, seen in the movingdirection of the bivalve harvester 2, are staggered parallel to oneanother and spaced apart, so that the harvesting rollers 90 and 92 donot exert a clamping force on each other, but on the other hand aclamping force against the bivalves 6 and the bivalve net 10. Harvestingof the bivalves 6 takes place in that, in its position of use, thebivalve harvester 2 is moved in the moving direction of the propulsionrollers 86 and 88, while the harvesting rollers 90 and 92 are beingrotated at the desired and preferably equal peripheral speed and withthe desired compressive force against the bivalves 6 on the respectivesides of the bivalve net 10. Seen from above and in the direction ofmotion, the harvesting roller 92 on the right-hand side of the bivalvenet 10 must be rotated clockwise, whereas the harvesting roller 90 onthe left-hand side of the bivalve net 10 must be rotated anti-clockwise.The indicated rotary motion of the harvesting rollers 90 and 92, seen inrelation to the rotary motion of the propulsion rollers 86 and 88,cooperate so that the bivalve net 10 is pulled in opposite directions bythe front and rear pairs of rollers, so that the bivalve net 10 isthereby held tightened. At the same time, in this exemplary embodiment,each harvesting roller 90 and 92 is formed on its cylindrical surfacewith profiled ribs 138 and 138′, projecting from said surface, cf. FIG.8. When the harvesting rollers 90 and 92 are rotated during harvesting,the ribs 138 and 138′ will scrape or mill the bivalves 6 off the bivalvenet 10.

[0067] When the bivalves 6 are being tended, as the tending rollers 94and 96 are rotating, the bivalves 6 are scraped or brushed. To removeunwanted organisms, e.g. starfish, the bivalves 6 are brushedsufficiently hard for starfish, for example, to come loose from thebivalves 6, but without the bivalves 6 thereby coming loose from thebivalve net 10. When the stock of bivalves is being thinned, all or someof the bivalves 6 on one side of the bivalve net 10, for example, arescraped or milled, so that the bivalves 6 come loose and fall off thebivalve net 10. FIG. 9 shows a tending or cleaning roller 94′ or 96,which is formed at its outer surface with threads 140 projecting fromthe surface of the roller 94 or 96. During tending or cleaning of thebivalve net 10, as the tending or cleaning rollers 94 and/or 96 arebeing rotated, the threads 140 are scraped or rubbed against acooperatingly positioned and stationary tending or cleaning brush 142cf. FIG. 9′, the brush 142 being formed of a longitudinal strip 144 withattached threads 146. The brush 142 is positioned longitudinallyparallel to the longitudinal axis of each tending or cleaning roller 94and/or 96, the strip 144 being secured for example to the frame part 18and/or 20 in its position of use. In this way, for example starfish,plastic bags, drift wood or other organic or inorganic waste can therebybe removed from-the bivalves 6 and/or the bivalve net 10. When removingstarfish, for example, the distance between the bivalves 6 and thetending roller 94 and/or 96 should be adjusted to the required degreefor the bivalves 6 not to come loose from the bivalve net 10, and at thesame time for the bivalves 6 not to be crushed or damaged. When thebivalve stock is being thinned, or when the bivalve net 10 is beingcleaned, the distance between the bivalves 6, possibly the bivalve net10, and the tending or cleaning rollers 94 and/or 96 is adjusted to therequired degree for the bivalves 6 or waste organisms/waste to comeloose from the bivalve net 10.

[0068] In the same manner as for the support and operation of thepropulsion rollers 86 and 88, each harvesting roller 90 and 92, possiblyeach tending or cleaning roller 94 and 96, is provided with alongitudinally through and rotatable centre axle 148 and 150, each ofthe centre axles 148 and 150 being secured at its end portions to arespective harvesting roller 90 and 92, possibly a respective harvestingor cleaning roller 94 and 96, by means of two circular mounting plates152 and 154, each of which provided with a centred hole 156 or 158,through which the centre axle 148 or 150 is passed, cf. FIGS. 8 and 9.To provide the necessary rotary motion, each centre axle 148 and 150 hasat its lower end portion in the position of use, a separate hydraulicmotor 160 and 162, which is for example remotely controlled, infinitelyvariable and reversible. In an alternative, not shown, only one of theharvesting rollers 90 and 92, possibly one of the tending or cleaningrollers 94 and 96, is rotated by a hydraulic motor 160 or 162. In useeach harvesting roller 90 and 92, possibly each tending or cleaningroller 94 and 96, is rotated at preferably equal peripheral speed. Themotors 160 and 162 are each secured to a respective distance element 164and 166, which are arranged to a mounting plate 168 and 170 each, eachmounting plate 168 and 170 being arranged to a respective frame part 18and 20. In addition each harvesting roller 90 and 92, possibly eachtending or cleaning roller 94 and 96, is releasably supported at itsupper end portions on a respective bearing pedestal 172 and 174, whichare each secured to a respective spacer element 176 and 177, the spacerelements 176 and 177 being arranged to a frame part 18 and 20 each, bymeans of a respective mounting plate 178 and 179.

[0069] The bivalves 6, or the waste organisms/waste separated from thebivalve net 10, are then: caught by an inlet manifold 180, the manifold180 being formed in its position of use, in this exemplary embodiment,by a vertical and elongate manifold funnel 182 of a square cross-sectionin a plan view. Longitudinally and parallel to the bivalve net 10, theinlet manifold 180 is divided into two for example equally largemanifold halves 184 and 184′, the manifold half 184 being securedinternally on the frame part 18., and the manifold half 184′ beingsecured internally on the frame part 20. In its position of use, theinlet manifold 180 encloses the harvesting rollers 90, 92, possibly thetending or cleaning rollers 94 and 96, and part of the bivalve net 10with attached bivalves 6, possibly waste and/or unwanted organisms, e.g.starfish. The manifold halves 184 and 184′ are spaced sufficiently fromthe bivalve net 10 for the manifold halves 184 and 184′ not to catch onthe bivalve net 10 in the harvesting or tending of the bivalves 6,possibly in the cleaning of the bivalve net 10. Additionally, along eachof its vertical and opposite end portions, each manifold half 184 and184′ is provided with two vertical and longitudinal rubber strips 186and 186′ and 188 and 188′, so that the rubber strips 186 and 186′project near to the bivalve net 10 and towards the rubber strips 188 and188′ on the other side of the bivalve net 10.

[0070] Loosened bivalves 6 or waste are/is then sucked into a flow ofwater, which is flowing, by means of a pumping device described later,essentially into the upper and open end portion of the inlet manifold180, but also partly through open gaps between the two manifold halves184 and 184′. The water 4 and the loosened bivalves 6, possibly wasteand/or unwanted organisms, are flowing further in the downstreamdirection through the manifold funnel 182 positioned in the lowerportion of the inlet manifold 180 and further through an opening 190formed in an upper end portion of a so-called debunching pipe 192 tocorrespond with the manifold funnel 182. In the same manner as that ofthe inlet manifold 180, the manifold funnel 182 is divided into two forexample equally large funnel halves 194 and 194′, the funnel half 194being arranged and connected to the manifold half 184, and the funnelhalf 194′ being arranged and connected to the manifold half 184′. Thefunnel half 194′ is permanently arranged about the opening 190 of thedebunching pipe 192, whereas the funnel half 194 is releasably arrangedround the opening 190 and is formed with for example a rubber seal 196,which bears, in its position of use, on the debunching pipe 192 and thevertical and opposite end portions of the other funnel half 194′. Whenthe bivalve harvester 2 is used, most of the water 4 will thereby besucked in through the upper portion of the inlet manifold 180.

[0071] The debunching pipe 192 is formed by an elongate andhorizontal-lying pipe, placed in its position of use at the bottomportion of the bivalve harvester 2 and parallel to the floating tube 14.The debunching pipe 192 is used for breaking up, or debunch, bivalvebunches 8, as bivalves. 6 often grow together into bunches on thebivalve net 10, and after harvesting i.a. such bunches 8 will betransported together with the water 4 by means of the pumping deviceinto the debunching pipe 192. Along one of its side portions, thedebunching pipe 192 is arranged to the frame part 18 through twomounting plates 198 and 200, each having an angular stay 33 and 33′arranged thereto. The other side portion of the debunching pipe 192 isarranged to the frame part 20 by two mounting plates 202 and 204, eachhaving a respective connecting stay 206 and 208 arranged thereto. In itsposition of use the debunching pipe 192 is placed below the propulsionrollers 86 and 88 and the harvesting rollers 90 and 92, possibly thetending or cleaning rollers 94 and 96, so that the debunching pipe 192,during propulsion in the water 4, runs unobstructedly below the footline 15 of the bivalve net 10.

[0072] The debunching pipe 192, moreover being cylinder-shaped and madeup of two identical and releasable halves, not shown in the drawings, isarranged with a debunching device. The debunching device is formed of atleast one stator part 210, which cooperates with an adjacent rotor part212 to break apart bivalve bunches 8, the two cooperating parts 210 and212 being referred to in the following as a debunching unit. In thisexemplary embodiment, the debunching pipe 192 is longitudinally providedwith five such cooperating debunching units 213, 214, 216, 218 and 220.Each stator part 210 is releasably anchored in one of the inner mantlehalves of the debunching pipe 192, whereas each rotor part 212 isreleasably anchored to a rotary axle 222 located along the centre lineof the debunching pipe 192. Additionally, in this exemplary embodimentthe stator part 210 and the rotor part 212 of each debunching unit areprovided with wires 224. In another exemplary embodiment, not shown, thewires 224 could just as well have been exchanged or combined with vanes,blades or strings, or possibly different assemblies thereof, accordingto the targeted object.

[0073] The debunching pipe 192 is in two parts, because it should bepossible to replace, possibly repair, the rotary axle 222 or statorparts 210 and/or rotor parts 212, possibly individual vanes, blades,strings or threads.

[0074] In this example the wires 224 of a stator part 210 and a rotorpart 212 are disposed radially in the debunching pipe 192 and about thecentre line thereof, and so that the wires 224 have a uniform angledistance about a common imaginary circumferential line. For example inthe harvesting of bivalves 6 and bivalve bunches 8, the rotary axle 222is rotated so that the rotor part 212 rotates relative to thecooperating stator part 210. When a bivalve bunch 8 in the water flow iscarried into the gaps between the wires 224 in a stator part 210 and arotor part 212, the bivalve bunch 8 will, as a consequence of therelative movement of the stator part 210 and the rotor part 212, bebroken into smaller bivalve bunches 8 and individual bivalves 6. By theuse of vanes or blades, for example, instead of threads or strings, andwith the purpose of preventing the bivalves 6 from being crushed ordamaged, the vanes or blades may possibly be provided with, orcompletely or partially formed of, a suitable rubber or plastic materialor similar.

[0075] In this connection it is difficult to specify materials ormaterial compositions, configurations or combinations of configurationsof vanes, blades, threads or strings, as such decisions must be madeaccording to the relevant type and quantity of bivalves 6 which it isdesirable to harvest, and/or the speed desired for the harvesting of thebivalves 6.

[0076] In the exemplary embodiment the five debunching units 213, 214,216, 218 and 220 are spaced apart unevenly along the length of thedebunching pipe 192, the distance between the successive debunchingunits decreasing, seen in the downstream direction of the water 4flowing through the debunching pipe 192. The use of several suchdebunching units 213, 214, 216, 218 and 220 may be required in order tosplit the bivalve bunches 8 sufficiently well in several debunchingsteps. In principle the bivalve bunches 8 should have been separatedcompletely, or approximately completely; into individual bivalves 6after the last downstream debunching step. In the tending of bivalves 6,possibly cleaning of the bivalve net 10, the rotary axle 222 and therotor parts 212 attached thereto, and the stator part 210, should beremoved.

[0077] The rotary axle 222 is rotated by e.g. a remotely controlledinfinitely variable and reversible hydraulic motor 226, the motor 226being arranged to the rotary axle 222 at the downstream end portionthereof.

[0078] The water 4 flowing through the inlet manifold 180 and thedebunching pipe 192 is driven by a suitable hydraulic pump 228 connectedto a remotely controlled, infinitely variable and reversible hydraulicdriving motor 230. The pump 228 and the driving motor 230 are positionedimmediately downstream of the debunching pipe 192. After the finaldebunching step the individual bivalves 6 are transported further in thewater flow through a guide funnel 232 at a downstream end portion of thedebunching pipe 192, then through the pump 228 and further up to thevessel or similar device through a conveyor pipe 234 of a suitable typeand size. On the vessel or device the bivalves 6 may then be collectedin suitable containers, e.g. cases, for possible further processingand/or further transport. In the tending of the bivalves 6, possiblycleaning of the bivalve net 10, in this exemplary embodiment, unwantedorganisms, e.g. starfish, and/or other waste are transported through thedebunching pipe 192, the pump 228 and the conveyor pipe 234, so that theorganisms and/or the waste may be collected on the vessel or device.

1. A device, hereinafter denoted a bivalve harvester (2), for harvestingand tending, including thinning, farmed bivalves (6) that attach to andgrow on a net (10) in water (4), said harvester (2) also being intendedfor cleaning unwanted matter from the net (10) in water (4), said net(10) being arranged to a floating device, including a floating tube(14), for suspending the net (10) substantially vertically and extendingit horizontally in the water (4), said harvester (2) also being arrangedto at least one floating device (14, 78, 80) and at least one propulsiondevice for moving the harvester (2) horizontally in the water (4),wherein said bivalve harvester (2) consists of a frame provided with atleast one non-propulsion roller constituting at least one harvestingroller (90, 92) or, alternatively, at least one tending or cleaningroller (94, 96), the at least one roller (90, 92, 94, 96) beingrotatable about its longitudinal axis, and wherein said at least oneroller (90, 92, 94, 96), in its position of use, extends substantiallyvertically and parallel with the net (10), and wherein an outer surfaceof said at least one roller (90, 92, 94, 96) is provided with at leastone scraping, milling or brushing device, said attached matter beingremoved from the net (10) when said at least one roller (90, 92, 94, 96)is pressed and rotated against the net (10).
 2. A device according toclaim 1, wherein said frame of the bivalve harvester (2) consists of twocooperating and pivotably connected frame parts (18, 20), each framepart (18, 20) being provided with a top side (22, 24) and an oppositebottom side (26, 28), the top side (22, 24) and the bottom side (26, 28)being adjoined by means of at least one connecting side (30, 30′, 32,32′), and wherein the top sides (22, 24) are pivotably connected via atleast one hinge (36, 37) having a pivot axis which, in position of use,substantially is horizontal, thereby enabling the frame part (18, 20) toopen and close about said net (10), and wherein at least one of saidframe parts (18, 20) is provided with at least one non-propulsion roller(90, 92, 94, 96) extending from said top side (22, 24) to said bottomside (26, 28).
 3. A device according to claim 1, wherein at least abottom portion of said at least one non-propulsion roller (90, 92, 94,96), in its position of use, is enclosed by a catching device that isopen for water through-put and is provided with an outlet opening which,in position of use, is positioned underneath the at least onenon-propulsion roller (90, 92, 94, 96), said catching device thuscapturing material removed from the net (10) in a manner avoidingpotential crushing of live bivalves (6), and wherein the catchingdevice, for conveying said removed material away from the net (10), isconnected to a pump device and a downstream transport pipe (234).
 4. Adevice according to claim 2, wherein at least a bottom portion of saidat least one non-propulsion roller (90, 92, 94, 96), in its position ofuse, is enclosed by a catching device consisting of two catching deviceparts which cooperate in their position of use, each catching devicepart being arranged to a respective frame part (18, 20), said two-partcatching device being open for water through-put and being provided withan outlet opening which, in position of use, is positioned underneaththe at least one non-propulsion roller (90, 92, 94, 96), said catchingdevice thus capturing material removed from the net (10) in a manneravoiding potential crushing of live bivalves (6), and wherein thetwo-part catching device, for conveying said removed material away fromthe net (10), is connected to a pump device and a downstream transportpipe (234).
 5. A device according to claim 4, wherein each catchingdevice part consists of a manifold half (184, 184′) and an associatedfunnel half (194, 194′) that, in position of use, collectively form aninlet manifold (180) and an associated manifold funnel (182).
 6. Adevice according to claim 1, wherein said frame of the bivalve harvester(2) is provided with at least one propulsion roller (86, 88) beingrotatable about its longitudinal axis, and wherein said at least onepropulsion roller (86, 88), in its position of use, extendssubstantially vertically and parallel with the net (10) and ispositioned in a trailing position relative to said at least onenon-propulsion roller (90, 92, 94, 96).
 7. A device according to claim2, wherein at least one frame part (18, 20) of the bivalve harvester (2)is provided with at least one propulsion roller (86, 88) being rotatableabout its longitudinal axis, and wherein said least one propulsionroller (86, 88) extends between said top side (22, 24) and said bottomside (26, 28) of the frame part (18, 20), and wherein said at least onepropulsion roller (86, 88), in its position of use, extendssubstantially vertically and parallel with the net (10) and ispositioned in a trailing position relative to said at least onenon-propulsion roller (90, 92, 94, 96).
 8. A device according to claim2, wherein, in position of use, each non-propulsion roller (90, 92, 94,96) in a pair of such rollers is arranged to its own frame part (18,20), and wherein the rollers (90, 92, 94, 96) of said pair arepositioned immediately adjacent and parallel to one another.
 9. A deviceaccording to claim 7, wherein, in position of use, each propulsionroller (86, 88) in a pair of such rollers is arranged to its own framepart (18, 20), and wherein the propulsion rollers (86, 88) of said pairare positioned immediately adjacent and parallel to one another.
 10. Adevice according to claim 6, 7 or 9, wherein said propulsion roller (86,88) is provided with a propulsion promoting surface, including acylindrical and evenly formed rubber membrane (98, 98′), or a surfaceprovided with rubber knobs (100) or a surface provided with projectingteeth.
 11. A device according to one of the claims 1-5 or 8, wherein aharvesting roller (90, 92) has a surface provided with profiled ribs(138, 138′), strips, teeth, threads or brushes.
 12. A device accordingto one of the claims 1-5 or 8, wherein a tending or cleaning roller (94,96) has a surface provided with threads (104), strings or brushes.
 13. Adevice according to claim 3, 4 or 5, wherein a debunching pipe (192) forseparating clusters of bivalves (6), is connected downstream of saidcatching device.